Referring to FIG. 1, an air flow measuring device 100 is used to measure air flow from registers, diffusers and grilles for various reasons such as, to verify air flow distribution, balance buildings, and pinpoint air system deficiencies. Air flow measuring device 100 generally includes a hood 110 and base 120. The hood 110 channels air to the base 120. The base 120 includes a measuring device for measuring the air flow and a readout device.
Air flow is measured using the air flow measuring device 100 by holding and aligning the top of hood 100 against an air flow opening and reading the airflow measurement on the readout device such a digital display. However, air flow openings, such as registers, diffusers, and grills, exist in a variety of sizes. To accurately measure the air flow from an air flow opening, the size of the opening of hood 110 should be as close as possible to the size of the air flow opening. Accordingly, although hood 110 is typically collapsible to fit into a carrying case, because hood 110 is of a fixed size, technicians must carry around numerous hoods of a variety of sizes to take readings for common air flow openings. To measure the air flow of a particular air flow opening, the technician must measure the air flow opening and then select, unfold, and place the correct sized hood 110 (if available) on the base 120 to measure the air flow. Carrying around multiple hoods 110 is bulk and costly, and replacing a hood 110 on a base 120 to match the size of an air flow opening is tedious and time consuming.